Antiflood fountain pen



Feb. 16, 1954 WESSNER 4 2,669,223

' ANTIFLOOD FOUNTAIN PEN Filed Jan. 18, 1951 n. cHeNNEur ims lo 20 30'nucKNEss OF Amwm Ram-AL Patented Feb. 16, 1954 UNITED STATES PATENTOFFICE ANTIFLOOD FOUNTAIN PEN Benjamin F. Micssner, Morristown, N. J.

Application January .18, 1951, Serial No. 206,677

(Cl. mil-50) 9 Claims. 1

This invention relates to what I consider to be a new type of fountainpen. It is one of the objects of the invention to provide a fountain penwherein leakage due to internal over external air increase is prevented.A further ob- .ject of my invention is to provide a new and structionthat is extremely simple and low in cost of manufacture and yeteffective in its operation. These and other objects and advantages willappear from a reading of the following specification wherein,

Figure l is a view on a much enlarged scale of the parts, except the capwhich is not shown, in section except the air tube which is shown inelevation;

Figure 2 is a view of the upper end of the interior construction at theline 22;

Figure 3 is a longitudinal view of a modified arrangement of the airtube and associated part;

Figure 4 is a view at the line 44 of Figure 3';

Figure 5 is an end view of Figure 6 at the line 5-5;

Figure 6 is a part elevational and part sectional view on an enlargedscale of the air tube;

Figure l is a view similar to Figure 4 but of a modified construction;

Figure 8 is a curve showing the principles involved in my newconstruction. j In the various views wherein like numbers refer tocorresponding parts, I is the barrel of the pen made of suitable plasticmaterial which is transversely compressible but axially stifi. Thebarrel 1 is preferably made of transparent material such as Celluloidhaving a thickness of about .010 to .015 inch. Where a Celluloid is usedI prefer to impregnate its inner surface translucent or opaque, may beused or even thin stainless steel.

The barrel 1 is attached to a hood 2 which may be made of suitablematerial such as hard rubber or the equivalent. The hood 2 has the endwhich receives the barrel which is made in hollow cylindrical form andthe end of the barrel is attached thereto preferably by a forced fittingjoint 9 so that the elastic expansion of the barrel I will make a firmlyink tight yet sep arable joint, the surfaces of which are preferablycovered with silicone grease or the equivalent to assist in making thejoint and in keeping the same tight. Also is shown in the drawing thatthe joint is made so as to provide a smooth surface l0 between thebarrel I and ,the hood 2. The hood 2 tapers to a rounded point at H andhas one side ground ofi at an angle of about 30 to the hood axis formingan oval shaped hole. The hood 2 has three bores of different diameters.The inner bore I2 is about inch long and adjacent to this is a somewhatlarger bore 13 which is about inch long and the largest bore I4 is aboutinch long. In the bore I2 is force fitted an ink tight ink tube 3. I-have obtained very satisfactory results for this tube by using astainless steel hypodermic tubing having an outside diameter of .065inch and inside diameter of .046 inch. This tube extends from a, pointI5 adjacent the nibs I6 of the pen point 4,'to a point on the axis ofthe barrel l short of the longitudinal volumetric center of the barrelindicated by the broken line II. This inner end of the end tube 3 isflared outwardly into a small cup l9. Inside of the ink tube 3 is an'airtube 5 which is somewhat longer than the ink tube 3 so that it may beprojected slightly at both ends from the ink tube, which extends fromthe end [8 to the end 2| where it is anchored by soldering or spotwelding to an oval plate 20, which is positioned in the oval surfaceformed in the hood 2. This plate 20 encloses the oval hole in the hood 2and prevents ink from creeping into the open end 2| of the air tube 5.The air tube 5 has an outside diameter of approximately 2 to 4 milssmaller than the inside diameter-of the ink tube 3 so as to formtherebetween an annular capillary ink channel 6. I have obtained quitesatisfactory results for this air tube, another stainless hypodermicneedle like tube having an outside diameter of .042 inch and an insidediameter of .015 inch.

In order to get the capillary attraction I have found that surfaceswhich are etched, pitted or scored develop great capillary actionpreferably from other surfaces, and to this end as shown in Figures 5and 6 one way of securing the desired efiect is by forming on theoutside of the air tube a plurality of triangularly shaped grooves 23.Besides serving to increase the capillary action this scoring asillustrated in Figure 5 serves an additional purpose in that it is madeso that the edges of the scoring is such that the maximum diameteracross two opposite scored parts is slightly in excess of the insidediameter of the end tube 3 so that when the ink tube and air tube areassembled the air tube will be co-axially spaced within the ink tube. Asshown in Figure 1 the co-axial arrangement is at least partiallyprovided for by passing a thin stifi pin 24 through the upper end of theair tube 5 and anchoring its ends to the top .01" the cup it. Stillanother wayof obtainingco-axiality of the two tubes 3 and 5 is thatshown in Figure 3, wherein a strong ink resistant but wettable wire 22is spirally wound in a coarse manner around the tube 5, at least theends 25 and 'izfi being soldered or welded to the endsoi .a tube $315 ifnecessary the wire 22 may be fastened to the tube 51) at one or moreintermediate points. A still further way of co-axial arrangement asshown in Figure '7 is wherein the pipe 5a cor responding to pipe 5 isextruded so a rib 21 is positioned thereon in a spiral manner as :shownin Figure 7. it is to be meted from Figure "1 that pen 4has a splitshank' whichsecurely fits into the bore 13 of medium diameter in thehood '2 while the larger *bore 4'4 provides arrannular "space 1 outsidethe shank of the pen for cooperation with the space 8 provided by themedium -diameter bore P3,

In Fig '8 I have shown acurve made from measurement data to determinethe capillary action that goes I on within the pen constructed to theforegoing, this 'data being obtained "at clean wettable surfaces. ofannular channels in the f or rnof tubular boresin a glass tube having ann id 'dia e r ff- 35 in 'By-reference'tothe QlIlV6itfWl11 be observed tat t e h h 1 .1 11mb "of a e i trade f ounta e a afielfs m el "G n k i lr es n ersely with t e di t f he ca ar b0 ??-v li s'cur ha be s d o. etemine m dal mc ne s 9f the r v s ii/ k ch nn s de cribed 1. 9. 1 a hann d'8 n'i la ion tg he n h-0f h se h e s.- -T e b c a epre e t e adia bannethick.- n n m nd th dina s e r sentth rtical heighttowhichinkwillclimbtothe surface of a .vessel or besecur'ely 'heldj;i n the tube wh is r moedffrom "the essel- These r h i hts-Mathew in hich ca llar 2 611st a ce.s a tiona 121111 11 t e ink column in the ink tube. "Withincreasedheight f n -c l mn av wilL ull q he-e c ss and cause' d i i olth ih tb m end oilthe tube .or other channel. until the capillaryattraction .balances the, gravitational pull.

However, when ..the.capilla'r rforce the. tube lanc e a nl l P1111 he Jcol mn will still iiowqntoon be .absorheldby wet.- table. surface or.body contacting theilower ,end of. the tube. .Thus the. ink. so; held inthe tube is still. n an r vai bl f -e p ica cn. suc a writing on paperor the like.

The m -i l va e oi bhwrdi aws 9 hi curve will vary somewhat withlthe.nature-"pi the .material. comprising. the .capillary channel walls, I en th u h he e be a re cr ase or i the like- Such -.a curve then :as .Eig..8 is .plotted from .measurements of the capillary ."iorce, of annularchannels for the material and surfacesto be used! and-this curve.isused. for-,deterrnin ing-the radial thicknesses .oftheasereral; inkchannelsbeltween the reservoir and the; peninib-tips .inanerlationto thelengths ofthesenchannels. :Eoneaample ifvall of. the channel-surfaces!have: capile lary forcesv in accordance with: the :curve: ofrFig h 1 itand the ink tube has a length of 2% inches inspection of this curveindicates that the radial thickness of the annular ink channel must beno greater than 8 mils, in order for it to hold this 2% inch high columnof ink without over flowing.

Likewise, if as an Figure 1, the length of ink collector spaces 7 and 8are /2 inch. Their annular thicknesses must not exceed 20 mils, in ord rl1at he@an icen es he an -fi s may atleast balance the gravitationalpull on their continued columns of ink. Since the thickness, that is theinside diameter of the air tube is 15 mils, its capillary force even ifits bore were wcttable, could sustain an ink column of only aboutqlinchas shown on the curve of Fig. 8.

From the end it of the ink tube 3 ink, which ihaszfilled .thesmallcup,flows down through the annular channel 6 to its lower end l5. There itcontacts the under surface of the plate 20 and flows over its surface tothe pen bore and nibs, due both to gravitational and capillary action.It flows therefore into the annular collector space'8'and thence intoannular collectorspace 7. Air in these spaces escapes-aroundtheedges ofplate 26.

The butt end of :the nib slit in the pen point is preferably nomore-than'one'or =two rni1gwide. This-slit tapers to zero =wid-th-at thetip'cnds 9f the contacting nibs. The capillary force inthis slit istherefore very large and increasesat the tip end, so that this; will be-ink-charged-so long as there 'is ink above =it-as described. Thus-far Ihave considered only the lqlyd rostatic p-ressu-re due to gravity oftheink in'a'nnulanchannels fi, "l andj8.

In order thattheir containedink'columns rnay notoverflowwhenoverbalanced by -an addition, to their hydrostaticpressures-of the usual hydrodynamic pressures set up by the-usual-axialnotions nvq e ri n and. n hand n 5. 9 9 p ns 1 .65? "ch-3 1N 5 il? g q? sm w less in'radial-thickness than those values ind a d a sufficient 9ydrq t ti rmessu a1one," by the absc' evalues cf the curve shown im-isur 8 0 i s milar curves or ther ami k-Qh !l6 ?:y r a e ama seleiactof e etyfisthus prq d das az ua a a ns verflqfw hich. he ve ne q'n tlarge enough to operate satisfactorily ,forrsuch unu ual hyd aq namislly-s v lq .iq W rd ,presslilifi ldflit Ql1 'th$ hih 9 ,91 f r s m ewhen. the. me i dress d. hun down into an unyielding s aceas a 'fioorfhis ewt penf.nen with in tby su merging" its ters; aainksl ppl an iteena rnat l .trac ve ysqu beans releasi thebar relfacfewmi es. Sueansyersepressure redness themlmnet capacity of th..,b rel andforcesairout. ,Release,,of 1t 1is pressure,al* l w the e astic ba rel tos ring ba k I o .c lin d c.a Sha e thusr clu n the. nternalair,press'ureand allowing the now. higher g mastm sph rie s u e oiorcc in us t-sl h cu h both the airj'.tube 4 and .thelink channel .6; intothepenreserroir. -sincethecrczsssectionalareas of .the bore;.oi air tuber5, ,and oi tha nn ular hann S are.a prosimatelnecual.their in 319 raesar -a proxim el equal since thes vhave apprcximat lyceq alcross lseticnalaareas and lengths they will both carry approximately equaQmQUQtSDfvlIIK QQW-Q l d nne e ds-i to the barrel; tiens s fi es to file haw-cha t top nd -c -the tube amcrrtb tub le els ade'itneal 10 :9 atwartor r. overth squeezes across the section occupied by these ink tubefilled with ink. The annular ink collector spaces 1 and 8 will also befilled with ink.

' The aggregate amount of ink in the annular channel 6 and the annularcollector spaces 1 and 8, is sufiicient for a few pages of writingwithout further replenishment of this supply when this ink has beenwritten out'it is only necessary to tilt the pen to point up or to ahorizontal position, whereupon the rapid fiow of ink in the reservoirwill lodge another drop or two into the cup l9 and thus replenish thesupply. Should an ink droplet become lodged in the air tube 5 it willsoon be moved back into the reservoir or to the pen point by movement ofair into .or out of the pen. Likewise, a concurrent squeeze of thebarrel with the tilting on shaking of the pen will insure quick transferof the ink from the cup l9 or the open end of the air tube 5 to the penpoint.

It may thus be seen that this pen has a small reservoir in the form ofthe spaces 6, 1, and 8, and a main reservoir in the barrel I, and thatthese reservoirs are interconnected for ink passage in either direction,when the pen is filled as above stated; in either point-up or point-downposition. The non-wettability of the outer surface of ink tube 3prevents capillary rise of ink along and over the inner end of 3 to thechannel 5, when the pen is point down. When the pen is point up, thereis a completely effective air space between the ink in the reservoir andthe inner ends of tubes 3 and 5.

When the pen is horizontal, even though the ink level may be at orslightly below the axes of tubes 3 and 5, ink inflow to these tubes isprevented by the non-wettability of the ends of these tubes. Thisnon-wettability however does not prevent ink from flowing into the cupl9 as it flows rapidly past it in a penward direction. Once thus caughtin this cup the ink drop forms into a bell like mass in good capillaryconnection with the end of the channel 6. When the ink supply in thebarrel l becomes low, mere tilting of the pen may be insufilcient tolodge ink drops in the cup l9. Then a single axial shake of the pen willdo so.

If the pen, after writing, is capped and put in the users pocket, pointup, ink will remain in channels 6, 1, and 8, and held there by capillaryforce. Then upon reinversion for writing, it will be instantly availableat the pen point nib ends for writing.

The actual ink capacity of this pen filled as explained in aconventional size of 1 3' inch outside diameter by 4% inch longover-all, but exclusive of cap, not shown, is approximately 4 cc. whichis from four to six times that of conventional fountain pens of the samesize.

It has been noted that the cross-sectional areas of the ink tube boreand the channel 6 are approximately equal. In filling, as well as inexpulsion of overfilled ink, both of these passages are flushed byrapidly moving ink streams so that any sedimentary ink deposits on theirwalls, left from continued, emptiness of disuse, will be wetted andflushed out. This flushing out occurs of course, with each refillingoperation so that 6 these passages are maintained inoperable conditionwith ink in at least the barrel reservoir, these passages are bathed inaqueous vapors so'that sedimentation will not occur. It is evidenttherefore that this pen construction and operation meets all of theoperation conditions desiderataof fountain pens, most of which are notfound in such conventional pens. It is further evident from what hasbeen said that this pen is simple, durable, and effective, of lowmanufacturing cost, and attractive in appearance and that it has anexceptionally largeink capacity, with completely visible operation. Ofcourse many of the details can be varied without de- ..parting from thespirit of my invention and the scope of the appended claims.

Having thus describedmy invention, I claim: 1. A fountain pen havingahoodcarrying. a

pen with ink collector spaces around the shank of the pen, an ink barrelfastened to the hood,

the barrel being of elastic material transversely compressible butaxiallystiif, an ink tube securely carried by the hood and extending onthe barrel axis, from a point near the pen nibs to a point near thevolumetric center of the barrel, a complete air tube located in closelyspaced annular relationship within the ink tube, to promote capillaryaction between the tubes and extending from a point adjacent the openend of the ink tube to a point near the nibs of the pen.

2. A fountain pen as set forth in claim 1 further defined in that thespacing between the inner wall of the ink tube and the outer wall of theair tube is of the order of 2 mils in radial distance as and for thepurpose described.

3. A fountain pen as set forth in claim 1 further defined in that theinner end of the ink tube terminates in a cup as and for the purposedescribed.

4. A fountain pen as set forth in claim 1 further defined in that thespacing between the inner wall of the ink tube and the outer wall of theair tube is of the order of 2 mils in radial distance while the innerend of the ink tube terminates in a cup and means for centralizing theadjacent end of the air tube in the cup.

5. A fountain pen as set forth in claim 1 further defined in that theouter surface of the air tube has means thereon for promoting capillaryaction, said means comprising an outer scored surface made up of aplurality of projecting scores preferably extending longitudinally ofthe air tube.

6. A fountain pen as set forth in claim 1 further defined in that meansare provided for 00- axially aligning the air tube within the ink tubein said closely spaced, annular relationship, said means comprising, arelatively coarse spirally wound wire around the air tube and having itsends fastened to the ends of the air tube, said wire being preferablyink resistant but wettable.

'7. A fountain pen as set forth in claim 1 further defined in that meansare provided for coaxially aligning the air tube within the ink tube insaid closely spaced, annular relationship, said means comprising aspirally formed integral rib extending along the length of the air tube.

8. A fountain pen as set forth in claim 1 further defined in that thepen end of the hood terminates in an oval shaped hole and the air tubeterminates in an oval shaped plate that covers said oval hole in thehood as and for the purpose described.

9. A fountain pen with a hood having at one end a hollow cylindricallyshaped formation while

